Field of the Invention
The present disclosure relates to a sensor screen and a display device including the same, and more particularly to a sensor screen having a fingerprint recognition function and a display device including the same.
Discussion of the Related Art
With the development of computer technology, computer based systems applied to various utilities, such as notebook computers, tablet personal computers (PCs), smart phones, personal digital assistants (PDAs), automated teller machines (ATMs), and information systems have been developed. In general, the computer based systems store various data including secret information such as business information and business secret as well as personal information related to private affairs. Thus, it is required to strengthen security to protect the secret information.
To this end, fingerprint sensors have been developed to strengthen security by performing registration or certification of systems using fingerprints of human beings.
The fingerprint sensor is a sensor capable of sensing fingerprints of human beings. The fingerprint sensor is classified into an optical fingerprint sensor and a capacitive fingerprint sensor.
The optical fingerprint sensor utilizes a principle in which a light source, such as a light emitting diode (LED), emits light and senses the light reflected from ridges and valleys of a fingerprint through a CMOS image sensor. There are, however, some problems such as an increase in size due to the use of LEDs and a rise in product cost due to the use of expensive light source.
The capacitive fingerprint sensor utilizes a difference of electric charges charged between ridges and valley of the finger contacted thereto.
U.S. Patent Publication No. 2013/0307818 published on Nov. 21, 2013, and entitled “Capacitive Sensor Package” describes a related art capacitive fingerprint sensor.
The published capacitive fingerprint sensor is configured as an assembly form coupled with a particular push button. The capacitive fingerprint sensor includes a silicon wafer, on which a circuit for measuring a capacitance between the fingerprint (ridges and valleys) and a capacitive plate is printed.
In general, it is necessary for the capacitive fingerprint sensor described in US Patent Publication No. 2013/0307818 to have a high resolution sensor array and an integrated circuit (IC) for the fingerprint recognition processing because the finger's ridges and valleys have a very minute size of about 300 μm to about 500 μm. To this end, the capacitive fingerprint sensor utilizes the silicon wafer for integrating the IC with the sensor array.
However, in case of integrating the IC with the high resolution sensor array using the silicon wafer, it is necessary for the capacitive fingerprint sensor to have an assembly construction for coupling the fingerprint sensor with a push button. Accordingly, there are some problems such as a complicated construction and an increase in a non-display area (e.g., bezel area) in the optical fingerprint sensor due to the assembly construction. Also, there are other problems including the issue where the thickness is increased and an area for sensing the fingerprint depends on the size of the push button (e.g., a home key of a smart phone) because the push button overlaps the fingerprint sensor.